In the forthcoming year we intend to concentrate on generating sufficient data to quantify the spontaneous state-dependent modulation of trigeminal motoneuron membrane activity. We also will generate statistical descriptions of reticular induced depolarizing and hyperpolarizing potentials in trigeminal motoneurons. Various tests will be conducted to further refine our understanding of the spontaneous control and reticular modulation of trigeminal motoneuron activity during sleep and wakefulness; this will include examining the state-dependent response patterns in conjunction with orthodromic excitation and antidromic invasion of trigeminal motoneurons. Additionally changes in membrane resistance will be examined and compared with the response pattern of known synaptic inputs upon trigeminal motoneurons, such as those induced by excitation of the inferior alveolar nerve. This year we will also explore the spontaneous changes in trigeminal mesencephalic preterminal fiber excitability during wakefullness, quiet sleep and active sleep, and the preterminal excitability of trigeminal mesencephalic fibers following reticular conditioning stimuli during these states.